saw this report on afternoon siestas - http://www.msnbc.msn.com/id/17121410/site/newsweek/
and a while later, this bbc report - http://news.bbc.co.uk/1/hi/magazine/5122184.stm

and the sleeping story gets a bit serious now:
"Anyone who uses an alarm to get up hasn't accumulated as much sleep as his or her brain wants," says Mahowald. quoted from http://lifegetinit.fitdv.com/new/articles/article.html?artid=69

and http://www.siestaawareness.org/pages/siesta-facts.php  says:
Studies show that there is a strong biological tendency for humans to become tired and possibly fall asleep in the early or mid afternoon as well as at night.
They [NASA] discovered that after a short nap there was a 34% improvement in performance and 54% in alertness

and, wikipedia http://en.wikipedia.org/wiki/Siesta  has this
In Bangladesh and Indian Bengal, the word which describes the concept is bhat-ghum, literally meaning "rice-sleep" (nap after consuming rice).

and some more here - http://drdeborahserani.blogspot.com/2006/06/benefits-of-power-napping.html
 

woah!!